A Shear horizontal surface acoustic wave biosensor for a rapid and specific detection of d-serine

d -serine is an amino acid that has an important role in the regulation of N-methyl- d -aspartate (NMDA) signalling in the central nervous system. In fact, it acts as an endogenous co-agonist molecule for the NMDA receptor activation. Since an abnormal body level of d -amino acids is usually associated to different neurological diseases, it appears evident that it is of high interest to develop a fast and specific biosensor for the determination of d -serine. In this work, we report on the design and development of a surface acoustic wave (SAW) biosensor to detect the level of d -serine. The SAW-biosensor is based on the utilization of an inactivated form of the d -serine dehydratase isolated from Saccharomyces cerevisiae , a biomolecule that is able to specifically bind d -serine. In particular, we produced a PLP-reduced d -serine dehydratase biomolecule that was still able to bind d -serine and not to transform it into the product. The binding event between the “inactivated” d -serine dehydratase and d -serine was monitored by SAW delay-lines.